Section 171(2)(a) in The Gujarat Municipalities Act, 1963
(a)No building shall be newly constructed or reconstructed over any sewer, drain, culvert or gutter vested in a municipality, without the written consent of the Chief Officer, and the Chief Officer may by, written notice require any person who has so constructed or reconstructed any building without such written consent, to pull down or otherwise deal with the same as he may think fit.